Update ci.yml

Author: kislyuk

.github/workflows/ci.yml

@@ -9,7 +9,7 @@ jobs:
       max-parallel: 8
       matrix:
         os: [ubuntu-20.04, macos-10.15]
-        python-version: [3.6, 3.7, 3.8, 3.9]
+        python-version: [3.5, 3.6, 3.7, 3.8, 3.9]
     steps:
     - uses: actions/checkout@v1
     - name: Set up Python ${{ matrix.python-version }}